Process of desulphurizing and purifying petroleum oil



Jan. 3, 1928. I 1,654,581

R. CROSS PROCESS OF DESULPHURIZING AND PURIFYING PETROLEUM OIL FiledNOV. 21. 1923 6 THEFT/Ala 7'0 14/595 3 It 8 5 2 g R R k 6 IN VEN TOR. 4'

Wi l/ass: 4

latented Jan. 3, 1923.

usrrao s'ra'ras ROY CRQSS, O15 KANSAS CITY, MISSQUBI.

PROCESS OF DESULPHUBIZING AND PURIFYING PETROLEUM OIL.

Application filed l 'ovember 21, 1923. Serial No. 676,028.

This invention relates to improvement. in a process and apparatus fordesulphurlzlng and purifying petroleum 011, and refers more particularlyto a process in which oils aredesulphurized, decolorized,-puritied,deodorized and sweetened by treatment with a solution of metal salts attemperatures and pressures bestadapted to etfcct the most complete andeificient refining of the product treated.

Amongthe objects of the invention are to provide a process in whichpetroleum hydrocarbons, and particularly cracked distillates or oilscontaining objectionable amounts of 1 sulphur compound, may be-treatedwhereby the sulphur is removed and the oil sweetened and decolorized toproduce a water-white product; to provide a process whereby the oil maybe marketed directly after treatment, or when treating certain oilsespecially difiicult to refine, an additional bleaching material may beused subsequent to the purifyin treatment. Tn the drawings: 2 The singlefigure is a diagrammatic side 1 elevational view of the-apparatus withparts shown in section.

"While the apparatus, shown in the drawin'gs, discloses a constructionadaptable for the purpose described, it is understood that petroleumhydrocarbons may be treated by this process in other types of apparatuswithoutdeparting from the spirit of the invention.

Referring briefly to the drawings, at 1 is shown a heating coil mountedin a furnace 2, preferably heated by means of gas burner 3. Thedischarge end of the heating coil communicates with a chamber 4, whichhas connection through a transfer line 5 to the treating tower 6. Thetreating tower in turn communicates through a line 7 with a bleachingtower or stage 8; this latter zone being connected by line 9 to acooling coil 10. A receiving tank 11 is equipped with a liquid drawofiline 12, controlled by a valve 13.

Rgoferring now to the method in which the oil is" treated, thedistillate or petroleum hydrocarbon which is to be treated is introducedto the system for purifying, desulphurizing, deodorizing anddeeolorizing.

The hydrocarbon is supplied from any convenient source, not shown,through the pipe 1. This supply or charge is preferably con-- tinuouslydirected through the inlet line 14 and charged, by means of the pump15,v

through t e line 16 and thence through the heating oil 1 where it isheated to the desired treating temperature. The most efficienttemperatures utilized will vary with the type of oil treated, buttemperatures ranging from 200 to 500 F. will include a range which,normally, is suflicient to properly treat-the oils by this process. Atthis temperature, there are sufficient volatile prod ucts evolved togenerate a self-imposed pressure which is maintained upon the oilcollecting in the chamber 4:. Ifthe vapors, evolved at the temperaturesused, are insufiicient to generate the desired pressur,--an extraneousgas may be supplied through the pipe 17 controlled by a valve 18 or thepres sure built up by the pump 15. The chamber is equipped with apressure gau e 19Ifor ascertaining pressure maintame in the chamber.

A heated oil, under pressure, is discharged from the chamber through theline 5, controlled by a valve 20, and is conducted to the treating tower6. A bypass line 21, controlled b a valve 22, is connected between thechain er and the line 5 beyond the valve The tower 6 consists preferablyof a heavily insulated cylindrical chamber whichhaspositioned therein aplurality of bafile. n 1emhers 23 which serve to cause the oil to followa circuitous route in its travel from the bottom to the top of thetower. Between these bafiie members is positioned a plurality of screensor metal lath, diagrammatically shown at 24, broken stone or otherrelatively inert material which has the ability of increasing thesurface over which the oi is -passed in order that a more completetreatintimately combined in order that the treating material-introducedto the top shall be ,brought in contact with as much of the oil as ispossible in its travel. The treating solution consists of certain metalsalt such as lead, copper, antimony, zinc, manganese, or

other metals which have the ability of combining with the sulphur, andother impurities, to remove it from the oil. These metal salts aredissolved in such solvents as water, alcohols, glycerin,ethylene-glycol, or other solvent materials which do notreadily dissolvein the oil nor have the characteristicsof dissolving any substantialamount of. hydrocarbon material. The treating solutions which havebcenused with the most got satisfactory results are sodium-plumbite solutionknown in the art as a doctor solution, and copper solution preferably ina neutral or weak acid condition.

It is well known thatsodium plumbite solution has been used heretoforeas a cold solution in treating oils' toiremove a part of heir sulphurcontent, but it has-never been satisfactorily demonstrated that such asolution can extract effectively sulphur from oils which have anythingmore, than a very small amount of sulphur therein. This solution, whenused underheat and pressure conditions such as those described, may beeflectively utilized to treat the most odoriferous sulphur containinghydrocarbon products such as natural gasoline or cracked gasolinerecovered from Luling crude, which is notoriously high inits' sul hurcontent. The product resulting from t is treatment was a water-white,clean, sweet distillate which could readily pass both a doctor andcopper corrosion test. The oil, after treatment in t'hctower-G, passesover through the line 7 and may be withdrawn through the line 27controlled by a valve or if oil of a character which necessitatessubsequent bleaching, the valve 28 may be closed and the valve 29opened, whereupon the oil is introduced to a" bleaching stage whichconsists of a tower 30 filled, between the 'uppcr and lowerscreens,

- with fullers earth, b'ntonite, or other bleach ing material. Thislatter container is preferably"steam-jacketed, as shown at 32, for

maintaining the p roper heat during the bleaching treatment. The oil, onrising to the top of the container 8, flows off through the line 9,controlled bya valve 33, to a cool ing.,.coil 34'and is collected asrefined distillate in the receiving "tank 11 from which it may be dfwned as desired.

drawn off through the line 35 regulated In place of the bleaching stage,the ull withdrawn from the line 27, if not suf ficiently bleached, may:be subsequently subjected to a dilute' acid and caustic treatment incontinuous agitators not shown but in ra-ctice well known in the-"art;

' he treating substance, which is of heavier gravity than the oil, willfind its way to the bottom of a treating tower'6 and may Ihe. a valve36. This material may be settled out" and regenerated for reuse or,'ifsuch drawn oil as waste.

practice, is ineffective to thesatiefac tory ref covery of the material,it may simply be' As described, temperature range of from 200 to 500 F.results in the most satis-F factory treatment;."and pressures ranging.

from 25 to 150 pounds have proven to be satisfactory. -The function ofthe pressure lies not only in the maintaining of the treat ing materialor solution. in the liquid phase, but also in the fact that it tends to.combine more effectually and intimately the treating and treatedmaterial. The increase of temperature increases velocity of reactionamounting to doubling of the effectiveness for each 20 F. rise intemperature.

Normally, the hydrocarbons introduced I from the chamber into'thetreating tower, is in a. fluid state- A portion of the volatilehydrocarbons being in a vaporous condition, while a substantial portionof the oil being in a liquid state.

In the event that a regeneration of the treating material is notpractical, it may be desirable to distill off thesolvent material aftersuch liquids as alcohol. orglycerin is, used. This recovered solvent maysubse-.

quently recombined with'a fresh supply of metal salts for reuse.Considerable reviving of the treated material may be efiectedbymechanical filtration to remove the objection able impurities.

This treatment may also be used in' crackmg still towers for vaporsunder pressure or while the oil is in the vapor phase. I

When treating be'nzine dis'tillates where as subsequent distillation isnecessary to recover a satisfactory inarketable,gasolinedike I theliquid materials.

2. A process for purifying and decolorizing hydrocarbon oils, comprisingthe steps of. bringing the oil in intimate contact by counterflowing' itwith a sodium plumbite' solution, the solvent being substantiallyimmiscible in the oil, separating the oil and. treating materials andsubjecting the formal to the bleaching action of an adsorptivc agent andmaintaining the oil at temperatures above 200 F. andunder pressuresufficient to prevent substantial vaporiaation during operation.

7 nor cross.

